In early 2013, tumblr suffered a data breach which resulted in the exposure of over 65 million accounts. The data was later put up for sale on a dark market website and included email addresses and passwords stored as salted SHA1 hashes.
Accounts breached: 65469298
Breached on: February 28, 2013
Exposed data: Email addresses and Passwords
Added on: May 29, 2016